Combustor for gas turbine engine

Abstract

A gas turbine combustion includes a combustion chamber mounted within an air supply manifold. The combustion chamber preferably has a fixed downstream portion and a telescopically-movable upstream portion, a burner head provided with a fuel injector, and a primary air inlet from the manifold into the combustion chamber defined between the burner head and an upstream end of the telescopically-movable upstream portion. Movement of the upstream portion of the combustion chamber towards the burner head serves to restrict the primary air inlet while opening a secondary air inlet from the manifold into the combustion chamber downstream of the burner head. Movement of the upstream portion of the combustion chamber away from the burner head serves to open the primary air inlet while restricting the secondary air inlet.

I claim:  
     
       1. A gas turbine combustor, comprising: 
       a) a combustion chamber having first and second, hollow, chamber portions at least partly overlapping each other and being mounted for telescoping movement relative to each other along an axis between end-limiting positions;  
       b) an air supply manifold having primary and secondary air inlets spaced apart along the axis and being together operative for supplying air to the combustion chamber, the primary inlet having a variable cross-sectional area through which a primary part of the air flows into the combustion chamber, the secondary inlet being located at an overlapping region of the chamber portions and having a variable cross-sectional area through which a secondary part of the air flows into the combustion chamber;  
       c) a fuel injector for injecting fuel to the primary part of the air flowing into the combustion chamber;  
       d) a burner for combustion the fuel and the air within the combustion chamber; and  
       e) an actuator means for moving the chamber portions relative to each other in opposite directions along the axis between the end-limiting positions, and for varying the cross-sectional areas of the primary and secondary inlets in inverse proportion to each other during movement of the chamber portions.  
     
     
       2. The gas turbine combustor according to  claim 1 , in which each chamber portion has an annular chamber wall concentric with the axis. 
     
     
       3. The gas turbine combustor according to  claim 1 , in which the combustion chamber is mounted within the manifold. 
     
     
       4. The gas turbine combustor according to  claim 1 , in which the actuator means varies the cross-sectional area of the primary inlet to be at a maximum, and the cross-sectional area of the secondary inlet to be at a minimum, in one of the end-limiting positions. 
     
     
       5. The gas turbine combustor according to  claim 1 , in which the actuator means varies the cross-sectional area of the primary inlet to be at a minimum, and the cross-sectional area of the secondary inlet to be at a maximum, in one of the end-limiting positions. 
     
     
       6. The gas turbine combustor according to  claim 1 , in which the actuator means is operative for moving one of the chamber portions, and in which said one of the chamber portions has a boundary wall that bounds the primary inlet and that jointly moves with said one of the chamber portions to vary the cross-sectional area of the primary inlet. 
     
     
       7. The gas turbine combustor according to  claim 6 , in which the actuator means includes a rod extending parallel to the axis, and operatively connected to the boundary wall. 
     
     
       8. The gas turbine combustor according to  claim 6 , wherein said one of the chamber portions has a lip extending parallel to the axis. 
     
     
       9. The gas turbine combustor according to  claim 1 , in which the secondary inlet has an aperture extending through one of the chamber portions at the overlapping region. 
     
     
       10. The gas turbine combustor according to  claim 1 , in which the secondary inlet has an aperture extending through each of the chamber portions at the overlapping region. 
     
     
       11. The gas turbine combustor according to  claim 1 , and further comprising a seal in sealing engagement between the chamber portions at the overlapping region. 
     
     
       12. The gas turbine combustor according to  claim 1 , and further comprising a pair of seals spaced apart along the axis, each seal being in sealing engagement between the chamber portions at the overlapping region. 
     
     
       13. The gas turbine combustor according to  claim 1 , in which the actuator means is operative for moving one of the chamber portions, and in which the other of the chamber portions is fixed to the manifold. 
     
     
       14. The gas turbine combustor according to  claim 13 , in which said one chamber portion is slidably mounted inside said other chamber portion. 
     
     
       15. The gas turbine combustor according to  claim 13 , in which said one chamber portion is slidably mounted outside said other chamber portion. 
     
     
       16. The gas turbine combustor according to  claim 1 , in which the first chamber portion receives the fuel and the primary part of the air for combustion, and wherein the second chamber portion,receives the secondary part of the air. 
     
     
       17. The gas turbine combustor according to  claim 1 , in which one of the chamber portions overlies an entire length of the other of the chamber portions. 
     
     
       18. A gas turbine engine operative between a maximum load condition and a low-load condition, comprising: a gas turbine combustor, including: 
       a) a combustion chamber having first and second, hollow, chamber portions at least partly overlapping each other and being mounted for telescoping movement relative to each other along an axis between end-limiting positions corresponding to the maximum load and no-load conditions;  
       b) an air supply manifold having primary and secondary air inlets spaced apart along the axis and being together operative for supplying air to the combustion chamber, the primary inlet having a variable cross-sectional area through which a primary part of the air flows into the combustion chamber, the secondary inlet being located at an overlapping region of the chamber portions and having a variable cross-sectional area through which a secondary part of the air flows into the combustion chamber;  
       c) a fuel injector for injecting fuel to the primary part of the air flowing into the combustion chamber;  
       d) a burner for combustion the fuel and the air within the combustion chamber; and  
       e) an actuator means for moving the chamber portions relative to each other in opposite directions along the axis between the end-limiting positions, and for varying the cross-sectional areas of the primary and secondary inlets in inverse proportion to each other during movement of the chamber portions.  
     
     
       19. The engine according to  claim 18 , in which the actuator means is operative for moving one of the chamber portions, and in which the other of the chamber portions is fixed relative to the manifold, and in which the actuator means includes at least one rod parallel to the axis and operatively connected to said one chamber portion to move the latter toward the burner as the engine load decreases toward the low-load condition, and away from the burner as the engine load increases toward the maximum load condition. 
     
     
       20. The engine according to  claim 19 , in which said one chamber portion has a lip extending parallel to the axis and jointly movable with said one chamber portion.